It's a nice time to ride our motorcycles; you've given your tires the once over, your engine's been treated to fresh oil, and even your brakes have been renewed. But when was the last time you thought about your motorcycle's cooling system? If you're the owner of an air-cooled motorcycle then you can be excused, but as most modern motorcycles are liquid-cooled then it's time you spared a thought for this vital part of your motorcycle.
We say motorcycles are liquid-cooled, what is basically done with a coolant, a mixture of anti-corrosion inhibitors, antifreeze and lubrication agents. Pouring water in the top of your radiator should only be done as a temporary measure or in a roadside emergency. The cooling system itself is straightforward: a radiator, pump and thermostat all joined together by an array of pipes and internal waterways. The radiator is the most intricate part, it relies on air flowing through hundreds of symmetrically arranged fins that have been heater by the coolant, dissipating heat as it does so. However the radiator and its delicate labyrinth of fins and narrow waterways needs to be kept clean; a build-up of road dirt and scuzz will affect its efficiency by clogging up the tiny air gaps.
When it comes to coolant, always use what is recommended by your motorcycle's manufacturer. This may sound simplistic but some types of coolant are specifically designed to be used in aluminum engines and any wrong choice can have horrible repercussions. The specific properties of coolant made for alloy engines differs from a more generic automotive product that is designed to protect cast iron or steel based engines.